CN111937493A - Sealing agent for organic EL display element and top emission type organic EL display element - Google Patents

Abstract

An object of the present invention is to provide a sealing compound for an organic EL display element which is excellent in inkjet coatability and can obtain an organic EL display element excellent in top emission type display performance. Moreover, the objective of this invention is to provide the top emission type organic EL display element using this sealing compound for organic EL display elements. The present invention is a sealant for organic EL display elements, which contains a polymerizable compound and a polymerization initiator, has a curing shrinkage rate of less than 11%, and is thermally desorbed by a thermal desorption GC-MS method at 80° C. for 30 minutes. The outgas generation amount of the cured product measured under the attached conditions was less than 3000 ppm.

Description

Sealant for organic EL display element and top emission type organic EL display element

technical field

The present invention relates to a sealing compound for an organic EL display element which is excellent in inkjet coatability and can obtain an organic EL display element excellent in top emission type display performance. Moreover, this invention relates to the top emission type organic EL display element using this sealing compound for organic EL display elements.

Background technique

An organic electroluminescence (hereinafter also referred to as "organic EL") display element has a laminate structure in which an organic light-emitting material layer is sandwiched between a pair of electrodes facing each other, and electrons are injected into the organic light-emitting material layer from one electrode, And holes are injected into the organic light-emitting material layer from the other electrode, so that electrons and holes are combined in the organic light-emitting material layer to emit light. As described above, since the organic EL display element emits light by itself, it has advantages such as better visibility, thinner thickness, and DC low-voltage driving, as compared with liquid crystal display elements that require a backlight.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2007-115692

Patent Document 2: Japanese Patent Laid-Open No. 2009-051980

SUMMARY OF THE INVENTION

The problem to be solved by the invention

The organic light-emitting material layer and electrode constituting the organic EL display element have a problem that the characteristics are easily deteriorated by moisture, oxygen, and the like. Therefore, in order to obtain a practical organic EL display element, the organic light-emitting material layer and the electrode need to be blocked from the atmosphere to achieve a longer lifetime. As a method of blocking the organic light-emitting material layer and the electrode from the atmosphere, an operation of sealing an organic EL display element with a sealant has been performed (for example, Patent Document 1). When sealing an organic EL display element with a sealant, in order to sufficiently suppress the permeation of moisture, oxygen, etc., an inorganic film called a passivation film is usually provided on a laminate having an organic light-emitting material layer, and a sealant is used. A method of sealing the inorganic film.

In recent years, instead of bottom-emission type organic EL display elements in which light emitted from the organic light-emitting material layer is extracted from the substrate surface side where the light-emitting element is formed, top-emission type organic EL display elements in which light is extracted from the upper surface of the organic light-emitting layer have received Attention. This method has the advantages that the aperture ratio (Japanese: aperture ratio) is high, and the low-voltage drive is advantageous for long life. In such a top-emission type organic EL display element, the top side of the light-emitting layer needs to be transparent, so the top side of the light-emitting element is sealed by laminating a transparent moisture-proof substrate such as glass through a transparent sealing layer (for example, patent Reference 2).

As a method of forming a sealant layer, there is a method of applying a sealant on a substrate using an inkjet method and then curing the sealant. When such a coating method based on the inkjet method is used, the sealing layer can be formed at a high speed and uniformly. However, when a sealant suitable for coating by an inkjet method is used in a top emission organic EL display element, there is a problem that display defects such as dark spots may occur in the resulting organic EL display element. In particular, even if a sealant does not cause display failure in a bottom emission type, when it is used in an organic EL display element of a top emission type, display failure may occur.

An object of the present invention is to provide a sealing compound for an organic EL display element which is excellent in inkjet coatability and can obtain an organic EL display element excellent in top emission type display performance. Moreover, the objective of this invention is to provide the top emission type organic EL display element using this sealing compound for organic EL display elements.

means of solving problems

The present invention 1 is a sealant for organic EL display elements, which contains a polymerizable compound and a polymerization initiator, has a curing shrinkage rate of less than 11%, and is thermally desorbed by GC-MS The outgas generation amount of the cured product measured under the thermal desorption conditions of 80° C. and 30 minutes was less than 3000 ppm.

Moreover, this invention 2 is the sealing compound for organic EL display elements which is used for coating by the inkjet method, the sealing compound for organic EL display elements contains a polymerizable compound and a polymerization initiator, and the organic EL display element The curing shrinkage of the sealant was less than 11%, and the outgas generation amount of the cured product measured by the thermal desorption GC-MS method under the thermal desorption conditions of 80° C. and 30 minutes was less than 3000 ppm.

The present invention is described in detail below. In addition, the matter common to the sealing compound for organic EL display elements of this invention 1 and the sealing compound for organic EL display elements of this invention 2 is described as "the sealing compound for organic EL display elements of this invention".

In a top emission type organic EL display element, the cathode is thinned from the viewpoint of light transmittance, and the thinned cathode is easily affected by the sealing agent used for the sealing layer formed on the cathode. . The inventors of the present invention considered that, in a top emission type organic EL display element, due to the influence of such a sealant on the cathode, even a sealant that does not cause display defects in a bottom emission type organic EL display element may cause a display defect. bad cause.

Therefore, the inventors of the present invention have conducted studies on a sealant for organic EL display elements having excellent inkjet coatability, in which the curing shrinkage ratio and the outgas generation amount of the cured product measured under stricter conditions than conventional ones are respectively lower than specific value. As a result, the inventors have found that a sealant for organic EL display elements can be obtained which is excellent in inkjet coatability and can obtain an organic EL display element excellent in top emission type display performance, and completed the present invention.

The sealing compound for organic EL display elements of this invention can be used for coating by a non-heating inkjet method as an inkjet method, and can also be used for coating by a heating inkjet method.

It should be noted that, in this specification, the above-mentioned "non-heating inkjet method" is a method of inkjet coating at a coating head temperature of less than 28°C, and the above-mentioned "heated inkjet method" is a method of 28°C or higher. Method of inkjet coating by coating head temperature.

In the above-mentioned heated inkjet method, an inkjet coating head equipped with a heating mechanism is used. By mounting the heating mechanism in the ink jet coating head, the viscosity and surface tension can be reduced when the sealant for organic EL display elements is discharged.

As an inkjet coating head equipped with the said heating mechanism, the KM1024 series by Konica Minolta, the SG1024 series by Fuji Film Dimatix, etc. are mentioned, for example.

When using the sealing compound for organic EL display elements of this invention for application|coating by the said heated inkjet method, it is preferable that the heating temperature of a coating head is the range of 28 degreeC - 80 degreeC. By making the heating temperature of the said coating head into this range, the time-dependent viscosity increase of the sealing compound for organic EL display elements is further suppressed, and discharge stability becomes more excellent.

The preferable lower limit of the viscosity at 25 degreeC of the sealing compound for organic EL display elements of this invention 1 is 5 mPa*s, and the preferable upper limit is 50 mPa*s. By making the viscosity at the said 25 degreeC into this range, it can apply|coat suitably by the inkjet method.

In addition, in this specification, the said "viscosity" means the value measured on the conditions of 25 degreeC and 100 rpm using an E-type viscometer. As said E-type viscometer, VISCOMETER TV-22 (made by Toki Sangyo Co., Ltd.) etc. are mentioned, for example, and the cone-plate of CP1 type can be used.

When applying by the above-mentioned non-heating inkjet method, the more preferable lower limit of the viscosity at 25° C. of the sealant for organic EL display elements of the present invention is 5 mPa·s, and the more preferable upper limit is 20 mPa·s . By making the said viscosity at 25 degreeC this range, it can apply|coat suitably by a non-heating inkjet method. When coating is performed by the above-mentioned non-heating inkjet method, the more preferable lower limit of the viscosity at 25° C. of the sealant for organic EL display elements of the present invention is 8 mPa·s, and the more preferable upper limit is 16 mPa·s , the particularly preferred lower limit is 10 mPa·s, and the particularly preferred upper limit is 13 mPa·s.

On the other hand, when it is used for coating by the above-mentioned heating inkjet method, the more preferable lower limit of the viscosity at 25° C. of the sealant for organic EL display elements of the present invention is 10 mPa·s, and more preferable The upper limit is 50 mPa·s. By making the said viscosity into this range, it can apply|coat suitably by the heating inkjet method. When it is used for application|coating by the said heating type inkjet method, the more preferable lower limit of the viscosity at 25 degreeC of the sealing compound for organic EL display elements of this invention is 20 mPa·s, and the more preferable upper limit is 40 mPa·s s.

The preferable minimum of the surface tension in 25 degreeC of the sealing compound for organic EL display elements of this invention 1 is 15 mN/m, and the preferable upper limit is 35 mN/m. By adjusting the surface tension at 25° C. to be in this range, it is possible to appropriately perform coating by the inkjet method. A more preferable lower limit of the surface tension at 25° C. is 20 mN/m, a more preferable upper limit is 30 mN/m, a further preferable lower limit is 22 mN/m, and a further preferable upper limit is 28 mN/m.

Moreover, the preferable minimum of the surface tension in 25 degreeC of the sealing compound for organic EL display elements of this invention 2 is 15 mN/m, and the preferable upper limit is 35 mN/m. By adjusting the surface tension at 25° C. to be in this range, it is possible to appropriately perform coating by the inkjet method. A more preferable lower limit of the surface tension at 25° C. is 20 mN/m, a more preferable upper limit is 30 mN/m, a further preferable lower limit is 22 mN/m, and a further preferable upper limit is 28 mN/m.

In addition, the said surface tension means the value measured by the Wilhelmy method by the dynamic wettability tester. As said dynamic wettability tester, WET-6100 type (made by RHESCA company) etc. are mentioned, for example.

The curing shrinkage rate of the sealant for organic EL display elements of the present invention is less than 11%. By making the said cure shrinkage rate less than 11 %, the sealing compound for organic electroluminescent display elements of this invention can obtain the organic electroluminescent display element excellent in top emission type display performance. A preferable upper limit of the curing shrinkage ratio is 10%, and a more preferable upper limit is 9%.

In addition, there is no particularly preferable lower limit for the above-mentioned curing shrinkage rate, but the substantial lower limit is 1%.

In addition, in this specification, the above-mentioned "curing shrinkage rate" refers to the specific gravity at 25°C of the sealant before curing as GA and the specific gravity of the cured product of the sealant at 25° _C as _GB by the following value calculated by the formula.

Curing shrinkage (%) ₌ ((GB _- GA)/ _GB )×100

In addition, the cured product used in the measurement of the above-mentioned specific gravity, if it is a photocurable sealant, can be obtained by, for example, irradiating the sealant with ultraviolet rays having a wavelength of 395 nm at 2000 mJ/cm ² with an LED lamp. A curable sealant can be obtained, for example, by heating at 80° C. for 1 hour.

The outgas generation amount of the cured product of the sealing compound for organic EL display elements of the present invention measured by the thermal desorption GC-MS method under the thermal desorption conditions of 80° C. and 30 minutes is less than 3000 ppm. By making the amount of outgas generation of the cured product measured by the thermal desorption GC-MS method less than 3000 ppm, the sealing compound for organic EL display elements of the present invention can obtain organic EL excellent in top emission type display performance. display element. The preferable upper limit of the degassing generation amount of the cured product measured by the thermal desorption GC-MS method is 2500 ppm, and a more preferable upper limit is 2000 ppm.

The degassing generation amount of the cured product measured by the thermal desorption GC-MS method is most preferably 0 ppm.

It should be noted that the measurement of the degas generation amount of the cured product by the thermal desorption GC-MS method can be performed as follows. The amount of gas components generated during heating under the thermal desorption conditions of ℃ and 30 minutes.

In addition, in the case of the cured product used for the measurement of the amount of outgas generation by thermal desorption GC-MS, if it is a photocurable sealant, for example, the sealant can be irradiated with a wavelength of 395 nm using an LED lamp. It can be obtained by ultraviolet 2000mJ/cm< ² >, and if it is a thermosetting sealant, it can be obtained by heating at 80 degreeC for 1 hour, for example.

With regard to other components such as the polymerizable compound, polymerization initiator, and sensitizer, which will be described later, by selecting their types and adjusting their content ratios, the above-mentioned viscosity at 25°C and the above-mentioned surface at 25°C can be adjusted. The tension, the above-mentioned curing shrinkage ratio, and the above-mentioned degassing generation amount of the cured product measured by the thermal desorption GC-MS method are within the above-mentioned ranges.

In particular, the above-mentioned curing shrinkage ratio and the above-mentioned degassing generation amount of the cured product measured by the thermal desorption GC-MS method are set within the above-mentioned ranges by selection of the type of the polymerizable compound described later and adjustment of the content ratio. made easy.

The sealing compound for organic EL display elements of this invention contains a polymerizable compound.

As the above-mentioned polymerizable compound, a cationically polymerizable compound and a radically polymerizable compound can be used. Among them, the above-mentioned polymerizable compound preferably contains a cationically polymerizable compound from the viewpoint of further reducing the curing shrinkage rate.

As said cationically polymerizable compound, an oxetane compound, an epoxy compound, a vinyl ether compound, etc. are mentioned, for example. Among them, the polymerizable compound preferably contains at least one of an oxetane compound and an epoxy compound, more preferably contains an oxetane compound, and further preferably contains a polyfunctional oxetane compound.

Examples of the oxetane compound include 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane, 3-ethyl-3-((2-ethylhexyloxy)methyl)oxetane, 3-ethyl-3-((3-(triethoxysilyl)propoxy) Methyl)oxetane, phenol novolac oxetane, 1,4-bis(((3-ethyl-3-oxetanyl)methoxy)methyl)methyl)benzene, etc. . Among them, 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane is preferable.

These oxetane compounds may be used alone or in combination of two or more.

Examples of the epoxy compound include 1,7-octadiene diepoxide, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol Glycol Diglycidyl Ether, Propylene Glycol Diglycidyl Ether, Dipropylene Glycol Diglycidyl Ether, Tripropylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl Ether, Glycerol Diglycidyl Ether, Trimethylolpropane Triglycidyl Ether, Phenyl glycidyl ether, phenylene diglycidyl ether, etc.

These epoxy compounds may be used alone or in combination of two or more.

Examples of the vinyl ether compound include benzyl vinyl ether, cyclohexanedimethanol monovinyl ether, dicyclopentadiene vinyl ether, 1,4-butanediol divinyl ether, and cyclohexane Alkane dimethanol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, etc.

These vinyl ether compounds may be used alone or in combination of two or more.

As the above-mentioned radically polymerizable compound, a (meth)acrylic compound is preferable.

In addition, in this specification, the said "(meth)acrylic" means acrylic or methacrylic, and the said "(meth)acrylic compound" means a compound having a (meth)acryloyl group , the above-mentioned "(meth)acryloyl group" refers to acryloyl group or methacryloyl group.

Examples of the (meth)acrylic compound include isobornyl (meth)acrylate, glycidyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9 -Nanediol di(meth)acrylate, Dicyclopentenyl (meth)acrylate, Dicyclopentenyloxyethyl (meth)acrylate, Dicyclopentyl (meth)acrylate, ( Benzyl meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate Acrylates, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate base) acrylate, lauryl (meth)acrylate, and the like. Among them, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentyl (meth)acrylate are preferable.

These (meth)acrylic compounds may be used alone or in combination of two or more.

In addition, in this specification, the said "(meth)acrylate" means acrylate or methacrylate.

The sealing compound for organic EL display elements of this invention contains a polymerization initiator.

As the above-mentioned polymerization initiator, a photocationic polymerization initiator and a photoradical polymerization initiator can be suitably used according to the type of the polymerizable compound to be used and the like. Moreover, a thermal cationic polymerization initiator and a thermal radical polymerization initiator can be used in the range which does not inhibit the objective of this invention.

The photocationic polymerization initiator described above is not particularly limited as long as it generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generating type or a nonionic photoacid generating type.

Examples of the anionic moiety of the ionic photoacid-generating photocationic polymerization initiator include BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , and (BX ₄ ) ⁻ (wherein X represents at least two or more fluorine or trifluoromethyl substituted phenyl) and the like. Moreover, as the said anion part, PF _m (C _n F _2n+1 ) _6-m ^- (wherein, in the formula, m is an integer of 0 or more and 5 or less, and n is an integer of 1 or more and 6 or less) )Wait.

Examples of the ionic photoacid-generating photocationic polymerization initiators include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, (2,4) having the above-mentioned anion moiety. -Cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt, etc.

As said aromatic sulfonium salt, for example, bis(4-(diphenylsulfonium)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonium)phenyl)sulfide bishexafluorophosphate, Fluoroantimonate, bis(4-(diphenylsulfonium)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonium)phenyl)sulfide tetrakis(pentafluorophenyl)boron acid salt, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(benzenethiol) Thio)phenylsulfonium tetrafluoroborate, diphenyl-4-(phenylthio)phenylsulfonium tetrakis(pentafluorophenyl)borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium Hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(bis(4-(2-hydroxyethoxy))benzene) sulfonium)phenyl)sulfide bis-hexafluorophosphate, bis(4-(bis(4-(2-hydroxyethoxy))phenylsulfonium)phenyl)sulfide bishexafluoroantimonate, bis(4-(bis(4-(2-hydroxyethoxy))phenylsulfonium)phenyl)sulfide 4-(bis(4-(2-hydroxyethoxy))phenylsulfonium)phenyl)sulfide bis-tetrafluoroborate, bis(4-(bis(4-(2-hydroxyethoxy)) Phenylsulfonium)phenyl)sulfide tetrakis(pentafluorophenyl)borate, tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate, and the like.

Examples of the above-mentioned aromatic iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, and diphenyliodonium Tetrakis(pentafluorophenyl) borate, bis(dodecylphenyl) iodonium hexafluorophosphate, bis(dodecylphenyl) iodonium hexafluoroantimonate, bis(dodecyl) Phenyl) iodonium tetrafluoroborate, bis(dodecylphenyl) iodonium tetrakis(pentafluorophenyl) borate, 4-methylphenyl-4-(1-methylethyl) Phenyl iodonium hexafluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyl iodonium hexafluoroantimonate, 4-methylphenyl-4-(1-methyl) Ethyl)phenyliodonium tetrafluoroborate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate, and the like.

Examples of the above-mentioned aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, phenyldiazonium tetrakis(pentafluoro) phenyl) borate, etc.

As said aromatic ammonium salt, 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl- 2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoro Phosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, 1-(naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate, etc.

As the above-mentioned (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt, for example, (2,4-cyclopentadien-1-yl) ((1-methylethyl)benzene)-Fe(II) hexafluorophosphate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) ) Hexafluoroantimonate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, (2,4-cyclopenta Dien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(pentafluorophenyl)borate and the like.

Examples of the above-mentioned nonionic photoacid-generating photocationic polymerization initiators include nitrobenzyl esters, sulfonic acid derivatives, phosphoric acid esters, phenolsulfonic acid esters, naphthoquinone diazonium, and N-hydroxyimidesulfonic acid. acid, etc.

As a commercial item among the said photocationic polymerization initiators, for example, a photocationic polymerization initiator by Midori Chemical Co., Ltd., a photocationic polymerization initiator by Union Carbide Co., Ltd., a photocationic polymerization initiator by Adeka Co., Ltd., 3M A photocationic polymerization initiator made by the company, a photocationic polymerization initiator made by BASF, a photocationic polymerization initiator made by Rhodia, a photocationic polymerization initiator made by San-Apro, and the like.

As a photocationic polymerization initiator by the said Midori Chemical Co., Ltd. product, DTS-200 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said Union Carbide company, UVI6990, UVI6974 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said ADEKA company, SP-150, SP-170, etc. are mentioned, for example.

As a photocationic polymerization initiator by the said 3M company, FC-508, FC-512 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said BASF company, IRGACURE261, IRGACURE290 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said Rhodia company, PI2074 etc. are mentioned, for example.

As a photocationic polymerization initiator by the said San-Apro company, CPI-100P, CPI-200K, CPI-210S etc. are mentioned, for example.

Examples of the photoradical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, benzil, thioxanthone-based compounds, etc.

As a commercial item among the said photoradical polymerization initiators, the photoradical polymerization initiator by BASF Corporation, the photoradical polymerization initiator by Tokyo Chemical Industry Co., Ltd., etc. are mentioned, for example.

As a photoradical polymerization initiator by the said BASF company, IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE651, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, Lucirin TPO etc. are mentioned, for example.

As a photoradical polymerization initiator by the said Tokyo Chemical Industry Co., Ltd. product, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, etc. are mentioned, for example.

Examples of the thermal cationic polymerization initiator include an anionic moiety composed of BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (wherein, X represents at least two or more fluorine or trifluoromethyl groups) substituted phenyl), sulfonium salts, phosphonium salts, ammonium salts, etc. Among them, sulfonium salts and ammonium salts are preferred.

As said sulfonium salt, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, etc. are mentioned.

As said phosphonium salt, ethyltriphenylphosphonium hexafluoroantimonate, tetrabutylphosphonium hexafluoroantimonate, etc. are mentioned.

Examples of the ammonium salts include dimethylphenyl(4-methoxybenzyl)ammonium hexafluorophosphate and dimethylphenyl(4-methoxybenzyl)ammonium hexafluoroantimonate. , dimethylphenyl(4-methoxybenzyl)ammonium tetrakis(pentafluorophenyl)borate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorophosphate, dimethylbenzene Alkyl(4-methylbenzyl)ammonium hexafluoroantimonate, dimethylphenyl(4-methylbenzyl)ammonium hexafluorotetrakis(pentafluorophenyl)borate, methylphenyldibenzyl Ammonium hexafluorophosphate, methylphenyldibenzylammonium hexafluoroantimonate, methylphenyldibenzylammonium tetrakis(pentafluorophenyl)borate, phenyltribenzylammonium tetrakis(pentafluorobenzene) yl) borate, dimethylphenyl(3,4-dimethylbenzyl)ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-N-benzylanilinium hexafluoro Antimonate, N,N-Diethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N,N-diethyl base-N-benzylpyridinium trifluoromethanesulfonic acid, etc.

As a commercial item among the said thermal cationic polymerization initiators, the thermal cationic polymerization initiator by Sanshin Chemical Industry Co., Ltd., the thermal cationic polymerization initiator by King Industries, etc. are mentioned, for example.

Examples of thermal cationic polymerization initiators manufactured by Sanshin Chemical Industry Co., Ltd. include San-Aid SI-60, San-Aid SI-80, San-Aid SI-B3, San-Aid SI-B3A, and San-Aid SI-B4, etc.

As a thermal cationic polymerization initiator by the said King Industries company, CXC1612, CXC1821 etc. are mentioned, for example.

As said thermal radical polymerization initiator, the thermal radical polymerization initiator containing an azo compound, an organic peroxide, etc. is mentioned, for example.

Examples of the above-mentioned azo compound include 2,2'-azobis(2,4-dimethylvaleronitrile), azobisisobutyronitrile, and the like.

Examples of the above-mentioned organic peroxides include benzoyl peroxide, ketone peroxide, ketal peroxide, hydrogen peroxide, dialkyl peroxides, peroxyesters, diacyl peroxides, and dioxy peroxides. carbonate, etc.

Among the above-mentioned thermal radical polymerization initiators, commercially available products include, for example, VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, and V-501 (all are Fuji Film Wako Pure Chemical Industries, Ltd. system) etc.

The preferable lower limit of the content of the polymerization initiator is 0.01 parts by weight, and the preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the polymerizable compound. Curability of the sealing compound for organic EL display elements obtained by making content of the said polymerization initiator 0.01 weight part or more becomes more excellent. By making content of the said polymerization initiator 10 weight part or less, the hardening reaction of the sealing compound for organic EL display elements obtained does not become too fast, workability|operativity becomes more excellent, and hardened|cured material can be made more uniform. The more preferable lower limit of content of the said polymerization initiator is 0.05 weight part, and a more preferable upper limit is 5 weight part.

The sealing compound for organic EL display elements of this invention may contain a sensitizer. The said sensitizer has the effect|action of further improving the polymerization initiation efficiency of the said polymerization initiator, and further promoting the hardening reaction of the sealing compound for organic EL display elements of this invention.

As said sensitizer, thioxanthone-type compound, 2, 2- dimethoxy- 1, 2- diphenyl ethane- 1-one, benzophenone, 2, 4- diphenyl ketone, Chlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, etc.

As said thioxanthone type compound, 2, 4- diethyl thioxanthone etc. are mentioned, for example.

The preferable lower limit of the content of the sensitizer is 0.01 parts by weight and the preferable upper limit is 3 parts by weight with respect to 100 parts by weight of the polymerizable compound. By making content of the said sensitizer into 0.01 weight part or more, a sensitization effect can be exhibited more. By making content of the said sensitizer 3 weight part or less, light can be transmitted to a deep part without becoming too large in absorption. The more preferable lower limit of content of the said sensitizer is 0.1 weight part, and a more preferable upper limit is 1 weight part.

The sealing compound for organic EL display elements of this invention may contain a thermosetting agent in the range which does not inhibit the objective of this invention.

As said thermosetting agent, a hydrazide compound, an imidazole derivative, an acid anhydride, dicyandiamide, a guanidine derivative, a modified aliphatic polyamine, addition products of various amines, and an epoxy resin, etc. are mentioned, for example.

Examples of the hydrazide compound include 1,3-bis(hydrazinocarbonylethyl (Japanese: ヒドラジノリルボノェチル))-5-isopropylhydantoin, sebacic acid dihydrazide, m-phenylene Diformic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, etc.

Examples of the above-mentioned imidazole derivatives include 1-cyanoethyl-2-phenylimidazole, N-(2-(2-methyl-1-imidazolyl)ethyl)urea, 2,4-di Amino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine, N,N'-bis(2-methyl-1-imidazolylethyl)urea, N, N'-(2-Methyl-1-imidazolylethyl)-adipamide, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-di Hydroxymethylimidazole etc.

As said acid anhydride, tetrahydrophthalic anhydride, ethylene glycol bis (dehydrate trimellitate), etc. are mentioned, for example.

These thermosetting agents may be used alone or in combination of two or more.

As a commercial item among the said thermosetting agents, the thermosetting agent by Otsuka Chemical Co., Ltd., the thermosetting agent by Ajinomoto Fine-Techno, etc. are mentioned, for example.

As a thermosetting agent by the said Otsuka Chemical Co., Ltd. product, SDH, ADH, etc. are mentioned, for example.

As a thermosetting agent by the said Ajinomoto Fine-Techno company, AMICURE VDH, AMICURE VDH-J, AMICURE UDH etc. are mentioned, for example.

The preferable lower limit of the content of the thermosetting agent is 0.5 parts by weight and the preferable upper limit is 30 parts by weight with respect to 100 parts by weight of the polymerizable compound. When the sealing compound for sealing compounds for organic EL display elements obtained by making content of the said thermosetting agent into this range is excellent in thermosetting property, while maintaining the outstanding storage stability. The more preferable lower limit of content of the said thermosetting agent is 1 weight part, and a more preferable upper limit is 15 weight part.

The sealing compound for organic EL display elements of this invention may contain a silane coupling agent. The said silane coupling agent has the effect|action which improves the adhesiveness of the sealing compound for organic EL display elements of this invention, a board|substrate, etc..

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-isocyanatopropylsilane. trimethoxysilane, etc. These silane coupling agents may be used alone or in combination of two or more.

The preferable lower limit of the content of the silane coupling agent is 0.1 parts by weight and the preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the polymerizable compound. By making content of the said silane coupling agent into this range, the effect of improving adhesiveness becomes more excellent, suppressing the bleed-out of excess silane coupling agent. The more preferable lower limit of content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 5 weight part.

The sealing compound for organic EL display elements of this invention may contain a surface modifier in the range which does not inhibit the objective of this invention. By containing the said surface modifier, the flatness of the coating film of the sealing compound for organic EL display elements of this invention can be improved further.

As said surface modifier, a surfactant, a leveling agent, etc. are mentioned, for example.

As said surface modifier, the surface modifier, such as a silicone type and a fluorine type, is mentioned, for example.

As a commercial item among the said surface modifiers, the surface modifier by BYK-CHEMIE JAPAN company, the surface modifier by AGC SEIMI CHEMICAL company etc. are mentioned, for example.

As a surface modifier by the said BYK-CHEMIE Japan company, BYK-340, BYK-345, etc. are mentioned, for example.

As a surface modifier by the said AGC SEMI CHEMICAL company, SurflonS-611 etc. are mentioned, for example.

The encapsulant for organic EL display elements of the present invention may contain a solvent for the purpose of viscosity adjustment, etc., but the remaining solvent may cause problems such as deterioration of the organic light-emitting material layer or occurrence of degassing, so it is preferable not to contain a solvent, or The content of the solvent is 0.05% by weight or less.

Moreover, the sealing compound for organic EL display elements of this invention can contain well-known various additives, such as a reinforcing agent, a softening agent, a plasticizer, a viscosity modifier, an ultraviolet absorber, an antioxidant, as needed.

As a method of producing the sealant for organic EL display elements of the present invention, for example, using a mixer such as a homogeneous disperser, a homogeneous mixer, a universal mixer, a planetary mixer, a kneader, and a three-roller, A method of mixing a polymerizable compound, a polymerization initiator, and additives such as a sensitizer and a surface modifier, and the like.

The preferable lower limit of the curing rate after 30 minutes from irradiation with ultraviolet rays of 2000 mJ/cm ² at a wavelength of 395 nm (hereinafter also referred to as "curing rate after 30 minutes from light") of the sealing compound for organic EL display elements of the present invention is 80%. By setting the curing rate after 30 minutes from light to 80% or more, the sealing compound for organic EL display elements of the present invention can reduce sol components and further reduce display defects. A more preferable lower limit of the curing rate after 30 minutes from light is 90%. Most preferably, the curing rate after 30 minutes from light is 100%.

In addition, in this specification, the above-mentioned "curing rate" is a value for the sealant before curing, the cured product of the sealant after 30 minutes from light, and the value after heating at 80°C for 1 hour from light. The cured product of the sealing compound was measured by FT-IR, and the value calculated by the following formula from the area value of the peak derived from the polymerizable functional group in the obtained spectrum.

Curing rate (%)=((1-y/x)/(1-z/x))×100

In the above formula, x is the peak area value derived from the polymerizable functional group of the sealant before curing. In the above formula, y is the peak area value derived from the polymerizable functional group of the cured product of the sealant after 30 minutes from light. In the above formula, z is the peak area value derived from the polymerizable functional group of the cured product of the sealant heated at 80° C. for 1 hour from light.

Regarding the peak derived from the polymerizable functional group, for example, when the polymerizable compound is an epoxy compound, it is a peak (911 cm ⁻¹ ) derived from an epoxy group, and when the polymerizable compound is an oxetane compound In the case of , it was a peak derived from oxetanyl group (978 cm ^-1 ).

The preferable minimum of the total light transmittance of the light of wavelength 380 nm or more and 800 nm or less of the hardened|cured material of the sealing compound for organic EL display elements of this invention is 80 %. By making the said total light transmittance 80 % or more, the optical characteristic of the organic electroluminescent display element obtained becomes more excellent. The more preferable lower limit of the said total light transmittance is 85%.

The said total light transmittance can be measured using, for example, a spectrometer such as AUTOMATIC HAZE METER MODEL TC-III DPK (manufactured by Tokyo Denshoku Corporation).

In addition, the cured product used for the measurement of the above-mentioned total light transmittance, if it is a photocurable sealant, can be obtained, for example, by irradiating the sealant with an ultraviolet ray of 2000 mJ/cm ² with a wavelength of 395 nm using an LED lamp, If it is a thermosetting sealant, it can be obtained by heating at 80 degreeC for 1 hour, for example.

Regarding the sealing compound for organic EL display elements of the present invention, it is preferable that the transmittance at 400 nm after irradiating the cured product with ultraviolet rays for 100 hours is 85% or more in an optical path length of 20 μm. By making the transmittance 85% or more after the above-mentioned ultraviolet irradiation for 100 hours, the transparency is high, the loss of light emission is reduced, and the color reproducibility becomes more excellent. A more preferable lower limit of the transmittance after 100 hours of ultraviolet irradiation is 90%, and a further preferable lower limit is 95%.

As a light source for irradiating the above-mentioned ultraviolet rays, for example, a conventionally known light source such as a xenon lamp and a carbon arc lamp can be used.

In addition, in the case of the cured product used in the measurement of the transmittance after 100 hours of ultraviolet irradiation, if it is a photocurable sealant, for example, the sealant can be irradiated with ultraviolet rays having a wavelength of 395 nm at 2000 mJ/ using an LED lamp. cm ² , and if it is a thermosetting sealant, it can be obtained by heating at 80° C. for 1 hour, for example.

The sealing compound for organic EL display elements of the present invention preferably has a moisture permeability of 100 g/m ² or less at a thickness of 100 μm measured by exposing the cured product to an environment of 85° C. and 85% RH for 24 hours in accordance with JIS Z 0208. By setting the above-mentioned moisture permeability to 100 g/m ² or less, the effect of preventing moisture from reaching the organic light-emitting material layer to cause dark spots becomes more excellent, and the reliability of the obtained organic EL display element becomes more excellent.

In addition, the cured product used for the measurement of the above-mentioned moisture permeability, if it is a photocurable sealant, can be obtained, for example, by irradiating the sealant with an LED lamp of 2000 mJ/cm ² of ultraviolet rays having a wavelength of 395 nm. A thermosetting sealant can be obtained, for example, by heating at 80° C. for 1 hour.

In the sealing compound for organic EL display elements of the present invention, it is preferable that the cured product has a moisture content of less than 0.5% after exposing the cured product to an environment of 85° C. and 85% RH for 24 hours. By making the moisture content of the cured product less than 0.5%, the effect of preventing deterioration of the organic light-emitting material layer due to moisture in the cured product becomes more excellent, and the reliability of the obtained organic EL display element becomes more excellent. The more preferable upper limit of the moisture content of the said hardened|cured material is 0.3 %.

As a measuring method of the said water content, the method of calculating|requiring by the Karl Fischer method based on JIS K7251, the method of calculating|requiring the weight gain after water absorption based on JIS K7209-2, etc. are mentioned, for example.

In addition, the cured product used for the measurement of the above-mentioned moisture content, if it is a photocurable sealant, can be obtained, for example, by irradiating the sealant with ultraviolet rays of 2000 mJ/cm ² with a wavelength of 395 nm using an LED lamp. A thermosetting sealant can be obtained, for example, by heating at 80° C. for 1 hour.

The sealing compound for organic EL display elements of this invention 1 can be used suitably for coating by the inkjet method, and the sealing compound for organic EL display elements of this invention 2 can be used for coating by the inkjet method.

As a method of producing an organic EL display element using the sealant for organic EL display elements of the present invention, for example, a method having a step of applying the sealant for organic EL display elements of the present invention on a substrate by an inkjet method, etc. The process of material, and the process of hardening the applied sealant for organic EL display elements by light irradiation and/or heating.

In the step of applying the sealant for organic EL display elements of the present invention to a substrate, the sealant for organic EL display elements of the present invention may be applied to the entire surface of the substrate, or may be applied to a part of the substrate. The shape of the sealing portion of the sealant for organic EL display elements of the present invention formed by coating is not particularly limited as long as it is a shape that can protect the laminate having the organic light-emitting material layer from outside air, and may be The shape which completely covers the laminated body may form a closed pattern in the peripheral part of the laminated body, or may form a pattern in the shape of a shape partially provided with an opening part in the peripheral part of the laminated body.

When curing the sealant for organic EL display elements of the present invention by light irradiation, by irradiating light with a wavelength of 300 nm or more and 400 nm or less and a cumulative light amount of 300 mJ/cm ² or more and 3000 mJ/cm ² or less, the present invention can be cured. The sealant for organic EL display elements is suitably cured.

Examples of the light source used for the above-mentioned illumination include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, excimer lasers, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, Sodium lamps, halogen lamps, xenon lamps, LED lamps, fluorescent lamps, sunlight, electron beam irradiation devices, etc. These light sources may be used alone or in combination of two or more.

These light sources can be appropriately selected according to the absorption wavelengths of the above-mentioned photoradical polymerization initiators and photocationic polymerization initiators.

As a method of irradiating the sealing agent for organic EL display elements of the present invention with light, for example, simultaneous irradiation of various light sources, sequential irradiation with a time difference, and irradiation combining simultaneous irradiation and sequential irradiation, etc. can be used, and any irradiation can be used. method.

The hardened|cured material obtained by the process of hardening the sealing compound for organic EL display elements by the said light irradiation and/or heating can be covered with an inorganic material film further.

As an inorganic material which comprises the said inorganic material film, the conventionally well-known inorganic material can be used, for example, silicon nitride ( _SiNx ), silicon oxide (SiOx), etc. are mentioned. The above-mentioned inorganic material film may be composed of one layer, or a plurality of layers may be laminated. In addition, the above-mentioned inorganic material film and the resin film containing the sealant for organic EL display elements of the present invention may be alternately repeated to cover the above-mentioned laminate.

The method for producing the above-mentioned organic EL display element may include a step of laminating the base material (hereinafter also referred to as "one base material") to which the sealant for organic EL display elements of the present invention has been applied and the other base material.

The base material (hereinafter, also referred to as "one base material") to which the sealant for organic EL display elements of the present invention is applied may be a base material on which a laminate having an organic light-emitting material layer is formed, or may not have the laminate formed thereon. body base.

When the above-mentioned one base material is a base material on which the above-mentioned laminated body is not formed, when the above-mentioned other base material is bonded, the organic EL display element of the present invention can be used so that the above-mentioned laminated body can be protected from external air. The sealant may be applied to one of the above-mentioned substrates. That is, it can be applied to the entire surface of the portion that will be the position of the laminate when it is bonded to another base material, or it can be completely included in the portion that will be the position of the laminate when it is bonded to another substrate. shape to form a closed pattern of sealant sections.

The above-mentioned step of curing the sealant for organic EL display elements by light and/or heating may be performed before the step of laminating the above-mentioned one substrate and the above-mentioned other substrate, or may be performed before the above-mentioned one substrate and the above-mentioned other. It is performed after the step of bonding the substrates.

When the step of curing the sealant for organic EL display elements by light and/or heating is performed before the step of bonding the above-mentioned one base material to the above-mentioned other base material, the sealant for organic EL display elements of the present invention In the case of an agent, it is preferable that the usable time after light irradiation and/or heating until the curing reaction progresses and adhesion becomes impossible is 1 minute or more. By setting the said usable time to 1 minute or more, it is possible to obtain higher adhesive strength without excessively advancing curing before bonding the one base material to the other base material.

In the step of laminating the one base material to the other base material, the method of laminating the one base material to the other base material is not particularly limited, but lamination is preferably performed under a reduced pressure atmosphere.

A preferable lower limit of the degree of vacuum in the above-mentioned reduced pressure atmosphere is 0.01 kPa, and a preferable upper limit is 10 kPa. By setting the degree of vacuum in the decompressed atmosphere within this range, it does not take a long time to achieve the vacuum state from the airtightness of the vacuum apparatus and the capability of the vacuum pump, and the one substrate and the other can be removed more efficiently. Air bubbles in the sealing compound for organic EL display elements of this invention when one base material is bonded together.

The sealing compound for organic EL display elements of this invention can be used suitably for sealing of a top emission type organic EL display element. The top emission type organic EL display element using the sealing compound for organic EL display elements of this invention is also one of this invention.

In addition, when the sealing compound for organic EL display elements of this invention is used for sealing of a bottom emission type organic EL display element, the organic EL display element excellent in display performance can be obtained.

Invention effect

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for organic electroluminescent display elements which is excellent in inkjet coatability and can obtain the organic electroluminescent display element excellent in top emission type display performance can be provided. Moreover, according to this invention, the top emission type organic EL display element using this sealing compound for organic EL display elements can be provided.

Detailed ways

Hereinafter, the present invention will be described in further detail by way of examples, but the present invention is not limited to these examples.

(Examples 1 to 4, Comparative Examples 1 to 3)

Example 1 was produced by uniformly stirring and mixing each material at a stirring speed of 3000 rpm using a homodispersing type stirring mixer (“Homodispersing Machine L Type”) according to the mixing ratio described in Table 1 at a stirring speed of 3000 rpm. -4. Each of the sealing compounds for organic EL display elements of Comparative Examples 1 to 3. About the obtained sealing compound for organic EL display elements, the hardened|cured material was obtained by irradiating the ultraviolet-ray 2000mJ/cm< ² > of wavelength 395nm with an LED lamp.

For each sealant for organic EL display elements obtained in the examples and comparative examples, an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., "VISCOMETER TV-22") was used at 25° C. and 100 rpm with a CP1-type cone and plate. Viscosity was measured under conditions. The results are shown in Table 1.

In addition, the surface tension of each sealant for organic EL display elements obtained in Examples and Comparative Examples was measured at 25°C using a dynamic wettability tester (manufactured by RHESCA, "WET-6100 type"). The results are shown in Table 1.

Moreover, the specific gravity of each sealing compound for organic EL display elements obtained by the Example and the comparative example, and hardened|cured material was measured. From the obtained specific gravity, the curing shrinkage rate was calculated by the above-mentioned formula. The results are shown in Table 1.

In addition, about 1 mg of each cured product obtained in the example and the comparative example, the amount of the gas component generated when heated under thermal desorption conditions of 80° C. and 30 minutes was measured using a thermal desorption apparatus and a GC-MS apparatus, and used as Degas production. Specific measurement conditions are shown below.

Thermal desorption device: Turbo Matrix 650 (manufactured by Perkin Elmer)

Thermal desorption conditions: 80°C, 30 minutes

Split flow (Japanese: スプリット): inlet 15mL/min, outlet 15mL/min, injection volume 5.2%

GC-MS apparatus: JMS Q1000 (manufactured by JEOL Ltd.)

Separation column: EQUITY-1 (non-polar)

0.32mm×60m×0.25μm

GC heating rate: 40°C for 4 minutes → 10°C/minute → 300°C for 10 minutes

Carrier gas (flow rate): He (1.5mL/min)

MS measurement range: 29 to 600amu (scanning 500ms)

Ionization voltage: 70eV

MS temperature: ion source 230°C, interface 250°C

The results are shown in Table 1.

<Evaluation>

The following evaluation was performed about each sealing compound for organic electroluminescent display elements obtained by the Example and the comparative example. The results are shown in Table 1.

In addition, in each evaluation of inkjet discharge property, wetting spreadability, and dark spot diameter enlargement ratio, IJH-30 (manufactured by IJT Corporation) was used as the coating head for inkjet, and the inkjet coating was not performed. It was performed under heating (coating head temperature 25°C).

(1) Inkjet coatability

(1-1) Inkjet Discharge Properties

Examples and Comparative Examples were coated on alkali-cleaned alkali-free glass (manufactured by Asahi Glass, "AN100") with a droplet volume of 10 picoliters using an ink jet discharge device (manufactured by MICROJET, "Nano Printer 500"). Each sealing compound for organic EL display elements obtained in. The case where the droplet was normally discharged from the inkjet nozzle and landed on the substrate was set as "○", and the case where the droplet was not normally discharged was set as "x", and the inkjet discharge property was evaluated.

(1-2) Wetting spreadability

Using an ink jet discharge apparatus (manufactured by MICROJET, "Nano Printer 500"), each sealant for organic EL display elements obtained in the Examples and Comparative Examples was sprayed at a speed of 5 m/sec with a droplet volume of 10 picoliters. 1,000 drops were applied on alkali-cleaned alkali-free glass (manufactured by Asahi Glass Co., Ltd., "AN100") at a pitch of 500 μm. The diameter of the droplet on the alkali-free glass 10 minutes after coating was measured, and the case where the diameter of the droplet was 150 μm or more was set as “○”, and the diameter of the droplet was 50 μm or more and less than 150 μm The case where the diameter of the droplet was less than 50 μm was set as “×”, and the wet spreadability was evaluated.

(2) Curing rate

For each of the sealing compounds for organic EL display elements obtained in Examples and Comparative Examples, FT- IR. From the area value of the peak (911 cm-1) derived from the epoxy group or the peak (978 cm-1) derived from the oxetanyl group in the obtained spectrum, the curing rate was calculated by the above formula.

(3) Light-emitting state of organic EL display element

A top emission type organic EL display element was obtained by the methods shown in the following (3-1) to (3-4). Moreover, about the obtained organic EL display element, the light emission state of the organic EL display element was evaluated by the method shown to the following (3-5) and (3-6).

(3-1) Preparation of a substrate on which a laminate having an organic light-emitting material layer is arranged

的厚度成膜了ITO电极的产物作为基板。将上述基板用丙酮、碱水溶液、离子交换水、异丙醇分别超声波清洗15分钟后，用煮沸的异丙醇清洗10分钟，进一步用UV-臭氧清洁器(日本laser电子公司制，“NL-UV253”)进行前处理。Will be on a glass substrate (length 25mm, width 25mm, thickness 0.7mm) or more

The thickness of the ITO electrode was filmed as a substrate. The substrates were ultrasonically cleaned with acetone, aqueous alkali solution, ion-exchanged water, and isopropanol for 15 minutes, respectively, and then cleaned with boiling isopropanol for 10 minutes, and further cleaned with a UV-ozone cleaner (manufactured by Japan Laser Electronics Co., Ltd., "NL- UV253") for pretreatment.

堆积于基板，形成膜厚

的空穴输送层。接着，将放入了Alq₃的坩埚加热，以

的蒸镀速度形成膜厚

的有机发光材料层。其后，将形成了空穴输送层和有机发光材料层的基板转移到另外的真空蒸镀装置中，在该真空蒸镀装置内的钨制电阻加热舟中放入氟化锂200mg、在另外的钨制舟中放入铝线1.0g。其后，将真空蒸镀装置的蒸镀器内减压至2×10^-4Pa，将氟化锂以

的蒸镀速度成膜

后，将铝以

的速度成膜

利用氮使蒸镀器内恢复常压，取出配置了具有10mm×10mm的有机发光材料层的层叠体的基板。Next, the substrate was fixed to a substrate holder of a vacuum evaporation apparatus, and N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (α- NPD) 200 mg, 200 mg of tris(8-hydroxyquinoline) aluminum (Alq ₃ ) was placed in a separate unglazed crucible, and the pressure was reduced to 1×10 ⁻⁴ Pa in a vacuum chamber. After that, the crucible in which the α-NPD was placed was heated so that the α-NPD was evaporated at the speed

deposited on the substrate to form a film thickness

the hole transport layer. Next, the crucible in which Alq ₃ was placed was heated to

The deposition rate of the deposition rate forms the film thickness

the organic light-emitting material layer. After that, the substrate on which the hole transport layer and the organic light-emitting material layer were formed was transferred to another vacuum deposition apparatus, and 200 mg of lithium fluoride was placed in a resistance heating boat made of tungsten in the vacuum deposition apparatus. Put 1.0g of aluminum wire into the tungsten boat. After that, the pressure inside the vapor deposition device of the vacuum vapor deposition apparatus was reduced to 2×10 ^-4 Pa, and lithium fluoride was

The evaporation rate of film formation

After that, the aluminum is

speed of film formation

The inside of the vapor deposition device was returned to normal pressure with nitrogen, and the substrate on which the laminate having the organic light-emitting material layer of 10 mm×10 mm was arranged was taken out.

(3-2) Coating with Inorganic Material Film A

A mask having an opening of 13 mm×13 mm was provided on the obtained substrate on which the laminate was arranged, and the inorganic material film A was formed by the plasma CVD method so as to cover the entire laminate.

The plasma CVD method was carried out under the following conditions: SiH ₄ gas and nitrogen gas were used as raw material gases, the flow rates of SiH ₄ gas were 10 sccm, nitrogen gas was 200 sccm, the RF power was 10 W (frequency: 2.45 GHz), and the temperature in the chamber was set to 10 sccm. was 100°C, and the pressure in the chamber was set to 0.9 Torr.

The thickness of the formed inorganic material film A was about 1 μm.

(3-3) Formation of Resin Protective Film

About the obtained board|substrate, each sealant for organic electroluminescent display elements obtained by the Example and the comparative example was apply|coated to the board|substrate pattern using the inkjet discharge apparatus (made by MICROJET company, "NanoPrinter300").

Then, using an LED lamp, it irradiated the ultraviolet-ray of wavelength 395nm of 2000mJ/cm< ² >, and the sealing compound for organic electroluminescent display elements was hardened, and the resin protective film was formed.

(3-4) Coating with Inorganic Material Film B

After the resin protective film was formed, a mask having an opening of 12 mm×12 mm was provided on the substrate, and an inorganic material film B was formed by plasma CVD so as to cover the entire resin protective film, thereby obtaining an organic EL display element.

The plasma CVD method is carried out under the same conditions as the above-mentioned "(3-2) Coating by Inorganic Material Film A".

The thickness of the formed inorganic material film B was about 1 μm.

(3-5) Measurement of initial dark spot diameter

About the obtained top emission type organic EL display element, the light emission state was observed with an optical microscope, and the initial dark spot diameter was measured. When there are multiple dark spots, the dark spots around 20 μm in diameter are preferentially observed.

(3-6) Enlargement rate of dark spot diameter

After exposing the obtained organic EL display element to an environment with a temperature of 85° C. and a humidity of 85% for 100 hours, a voltage of 3 V was applied, and the light-emitting state of the organic EL display element was observed with an optical microscope, in the same manner as in “(3-5)” above. The diameter of the dark spot after 100 hours at 85°C, 85%, and 100 hours was measured.

The case where the dark spot diameter enlargement ratio is less than 1.1 times is set as "◎", the case where it is 1.1 times or more and less than 1.2 times is set as "○", and the case where it is 1.2 times or more and less than 1.5 times is set as "Δ" was set as "X" when 1.5 times or more or the non-light-emitting portion was significantly enlarged, and the light-emitting state of the organic EL display element was evaluated.

The dark spot diameter enlargement ratio was calculated by the following formula.

Dark spot diameter enlargement rate=85°C, 85%, dark spot diameter after 100 hours/initial dark spot diameter

[Table 1]

Industrial Availability

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for organic electroluminescent display elements which is excellent in inkjet coatability and can obtain the organic electroluminescent display element excellent in top emission type display performance can be provided. Moreover, according to this invention, the top emission type organic EL display element using this sealing compound for organic EL display elements can be provided.

Claims (8)

1. A sealant for an organic EL display element, comprising a polymerizable compound and a polymerization initiator, The curing shrinkage of the sealing compound for organic EL display elements is less than 11%, and the sealing compound for organic EL display elements is measured by the thermal desorption GC-MS method under the thermal desorption conditions of 80° C. and 30 minutes. The outgas generation amount of the cured product of the sealant was less than 3000 ppm. 2. A sealant for an organic EL display element, characterized in that it is used in coating based on an inkjet method, The sealant for organic EL display elements contains a polymerizable compound and a polymerization initiator, The curing shrinkage of the sealing compound for organic EL display elements is less than 11%, and the sealing compound for organic EL display elements is measured by the thermal desorption GC-MS method under the thermal desorption conditions of 80° C. and 30 minutes. The outgas generation amount of the cured product of the sealant was less than 3000 ppm. 3 . The sealant for an organic EL display element according to claim 1 , which has a viscosity of 5 mPa·s or more and 50 mPa·s or less at 25° C., and a surface tension of 15 mN/m or more at 25° C. 3 . 35mN/m or less. 4 . The sealing compound for organic EL display elements according to claim 1 , wherein the polymerizable compound contains a cationically polymerizable compound. 5 . 5 . The sealing compound for organic EL display elements according to claim 4 , wherein the polymerizable compound contains a polyfunctional oxetane compound. 6 . 6 . The sealant for organic EL display elements according to claim 5 , wherein the polymerizable compound contains 3-ethyl-3-(((3-ethyloxetan-3-yl)methan. 7 . oxy)methyl)oxetane. 7. The encapsulant for organic EL display elements according to claim 1, 2, 3, 4, 5 or 6, which has a curing rate of 80% or more after 30 minutes of irradiation with ultraviolet rays having a wavelength of 395 nm of 2000 mJ/cm ² . 8 . A top emission type organic EL display element obtained by using the sealant for an organic EL display element according to claim 1 , 2 , 3 , 4 , 5 , 6 or 7 .